There is nothing to design. Sony designed the radio already. Millions of radios are made with the old IC.
If you can't get it then what are you going to do? Steal it from an old Sony Walkman radio?
afterall ready made radio is just few bucks? why design-- design something that is not readily avilable? or it is prohibitively costly.
btw, we can design and perhaps make it work bu can't generally hose it decently-- this the problem with many kits unless the kit maker gives you a cabinet for it.